I have been asked to create a notification that will text IT if any of our interfaces to DCS' stop communicating. Seems pretty easy to trigger an event based on the value of a tag, but can you trigger if the tag flatlines or has a bad status? Is there another way to approach the task?

If you implement NumOfChanges() or SecSinceChange() function, pay attention to the ExcMax setting of your watchdog tag. Generally, monitoring the Device Status, the Heartbeat, and the IO Rate would provide a good overview of the interface status.